title: Molecular characterization of tetracycline- and quinolone-resistant Aeromonas salmonicida isolated in Korea.
abstract: The antibiotic resistance of 16 Aeromonas (A.) salmonicida strains isolated from diseased fish and environmental samples in Korea from 2006 to 2009 were investigated in this study. Tetracycline or quinolone resistance was observed in eight and 16 of the isolates, respectively, based on the measured minimal inhibitory concentrations. Among the tetracycline-resistant strains, seven of the isolates harbored tetA gene and one isolate harbored tetE gene. Additionally, quinolone-resistance determining regions (QRDRs) consisting of the gyrA and parC genes were amplified and sequenced. Among the quinolone-resistant A. salmonicida strains, 15 harbored point mutations in the gyrA codon 83 which were responsible for the corresponding amino acid substitutions of Ser(83)→Arg(83) or Ser(83)→Asn(83). We detected no point mutations in other QRDRs, such as gyrA codons 87 and 92, and parC codons 80 and 84. Genetic similarity was assessed via pulsed-field gel electrophoresis, and the results indicated high clonality among the Korean antibiotic-resistant strains of A. salmonicida.
authors.affiliation: Laboratory of Aquatic Animal Medicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul 151-742, Korea.
authors.forename: Ji Hyung
authors.initials: JH
authors.lastname: Kim
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Hwang
authors.forename: Jee Soo
authors.initials: JS
authors.lastname: Son
authors.forename: Jee Eun
authors.initials: JE
authors.lastname: Han
authors.forename: Jin Woo
authors.initials: JW
authors.lastname: Jun
authors.forename: Sang Phil
authors.initials: SP
authors.lastname: Shin
authors.forename: Casiano
authors.initials: C
authors.lastname: Choresca
authors.forename: Yun Jaie
authors.initials: YJ
authors.lastname: Choi
authors.forename: Yong Ho
authors.initials: YH
authors.lastname: Park
authors.forename: Se Chang
authors.initials: SC
authors.lastname: Park
mesh_terms: D048409:Aeromonas salmonicida / Q000145:classification / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D024881:Drug Resistance, Bacterial; D004777:Environment; D005393:Fish Diseases / Q000382:microbiology*; D005399:Fishes; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology / Q000662:veterinary*; D008826:Microbial Sensitivity Tests; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D015363:Quinolones / Q000494:pharmacology*; D056910:Republic of Korea; D017421:Sequence Analysis; D013752:Tetracycline / Q000494:pharmacology*; D013753:Tetracycline Resistance
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D015363:Quinolones; D013752:Tetracycline